There is the problem of it replacing real jobs, but this is not unique to the field.
The main problem, in my eyes, is AI porn that mimics real people. This is the main place I'd like to see some real restriction.
There is a ginormous set of data available to nearly everyone for free. (one way or another) that would provide enormous training input.
If instead you focus on the fact that people were objektives during the making of the porn in the first place then the equatino changes.
In one case it would stop future objectification.
They also don't think about how easy it will be to identify them in the future as face recognition/matching gets even cheaper.
In this discussion your choice of words is very important.
So are those who are not offended that their employee did some nude modeling or sex work are... careless or inconsiderate in some way?
Should hiring or dating include some kind of background check based on puritanical definitions of "moral character"?
Perhaps people who think that way should wear some kind of scarlet letter. That way I can be sure they'll never be involved in my hiring pipeline.
Also those background checks won't be the official reason these people won't get hired, it's always easy to create an alternative reason, just how it works with agism, sexism and racism.
If they cared about their reputation, they wouldn't be porn stars
While we're at it, we should free up software developers to no longer have to have jobs where their body is on the line, with high rates of scoliosis and carpal tunnel too.
Taking away someone's livelihood without readily having an alternative to immediately substitute is rarely something you're going to be thanked for. There are absolutely abusive porn studios, but there's also a good portion of cottage industry "amateur" porn that's popped up in recent years, where the only "boss" is a site taking their overhead cost for hosting and distribution.
Not that I take issue with the march of progress here. Just saying that someone will be better off without their job is a bit off.
Controls and restrictions are good for people and thus society. We see benefits on limiting food intake, drugs, certain perversion (child, incest etc) and the inverse being no limits etc. associated with obesity, disease and mental health issues. IMO we shouldn't even coin the term "without hurting anyone" because of it's simplistic view of the world and society. AI porn will just feed peoples fetishes to no end and most likely compound the porn crisis further, which is already a public health issue.
This is the same argument used for a lot of things including drug addiction. It's a very easy phrase to throw without thinking of the wider consequences. People do not live in a bubble, we're social animals and another persons ills can have a detrimental effect on society.